Method and apparatus for creasing blanks



Aug. 16, 1960 1.. E. LA BOMBARD 2,949,066

METHOD AND APPARATUS FOR CREASING BLANKS Filed Jan. 20, 1958 9 Sheets-Sheet 1 INVENTOR. 3 Fi 1 LEONE. LABOMBARD BY P M v-Pamm ATTORNEYS Aug. 16, 1960 L. E. LA BOMBARD 2,949,066

METHOD AND APPARATUS FOR CREASING BLANKS Filed Jan. 20, 1958 A s Sheets-Sheet 2 1 23 \z 2 2 ig. 2.

Q r" g INVENTOR. J m LEONELLABQMBARD nny 5 BY 93 q N +7 N 5} ATTORNEYS Aug. 16, 1960 L. E. LA BOMBARD 2,949,065

METHOD AND APPARATUS FOR CREASING BLANKS Filed Jan. 20, 1958 9 Sheets-Sheet 3 IN VEN TOR. LEON E. LABOMBARD BY Pea/14m .PW A TT ORNEYS Aug. 16, 1960 L. E. LA BOMBARD 2,949,065

METHOD AND APPARATUS FOR CREASING BLANKS Filed Jan. 20, 1958 9 Sheets-Sheet 4 mulc'lnlcfil I'IE ,......mlm lli ululululul: 'l- I:

Z'IEII llll , INVENTOR. LEON E. LABOMBAKD BY PM PPM ATTORNEYS 1950 E. LA BOMBARD 2,949,066

METHOD AND APPARATUS FOR CREASING BLANKS Fi led Jan. 20, 1958 9 SheetsSheet 5 v 1 171 6 7 I I I I I \\i 16.9 164 nmmml 172 g 8. 168 15 25 w 234 172 -F1'g. .9.

36 INVENTOR.

3 LEON E. LABOMBARD 27 F 1g. 9A. 235 ATTORNEYS 6, 1960 L. E. LA BOMBARD 2,949,066

METHOD AND APPARATUS FOR CREASING BLANKS Filed Jan. 20, 1958 9 Sheets-Sheet 6 l I INVENTOR.

LEON E. LABOMBARD BY I P \J 1 15 M W" L g ATTORNEYS Aug. 16, 19.60 a... E. LA BOMBARD 2,949,065

' 7 METHOD AND APPARATUS FOR CREJASING BLANKS Filed Jan. 20, 1958" Y I 9 Sheets-Sheet 7 i I l Ill/l /////////////I I l/ I I I I I I I I l l I II INVENTOR. LEON E. LABOMBARD PW ATTORNEYS Aug. 16, 1960 1... E. LA BOMBARD 2, METHOD AND APPARATUS FOR CREASING BLANKS Filed Jan. 20, 1958 9 Sheets-Sheet 8 m mR. LEONE. LABOZVIBARD BY P v PW A T TORN E YS METHOD AND APPARATUS FOR CREASING BLANKS "Leon E. La Bombard, Nashua, N.H., assignor to The atent O,

International Paper Box Machine Company, Nashua,

-N .H.,-;a corporation of New Hampshire FiledJan. 20, 1958, Ser. No. 709,977

15 Jflaims. (Cl. 93-583) This invention relates to an .improved method and apparatus for accurately creasing corrugated-paperboard in the making of folding corrugated paper boxes.

In the prior art it-has been proposed to crease card board or corrugated board by means of pairs of opposed creaser bars of rigid material rotating or oscillating in parallelism along the path of advancing box blanks.

In US. Patent 1,772,785 to Smith of August 12, 1930, such creaser bars are proposed for applying both lateral and longitudinal creases to a continuous web of card board or to abutting blanks of card board. To avoid undesirable lateral strains on the webor blanks, or other difficulties, the longitudinal crease lines are applied along parallel longitudinal lines but alternately rather than simutaneously. The surface speed of the creaser bars'is the same as the speed of advance of the card board, or

abutting blanks, so that the creasing may be performed without any, or any appreciable, slipping or other harmvance at a uniform speed during creasing with no slippage of the blanks.

The creasing method and apparatus of this'invention departs from the teaching of the prior art in'advancing spaced, corrugated box blanks by friction belt carriers traveling at a predetermined speed while securing accurate registration of each successive blank by inducing slippage thereof relative to the carrier belts. Thus the carriers travel at a uniform speed but the blanks are temporarily retarded to the slower surface speed of the creaser bars and then released from the creaser bars to resume the speed of the carriers.

The principal object of' the invention is to provide a creasing method, and a creasing apparatus, which successfully pinch, crimp, or bead creases spaced blanks of corrugated paperboard while such blanks are advancing in untimed, relation at relatively high speed between friction belt carriers.

Another object of the invention is to temporarily register each successive blank just before it is creased even though the blanks continue advancing along a path through the creasing zone of the machine. Such reregistration squares the carton blank just prior to creas ing to insure absolute accuracy.

Another object of the invention is to provide high speed, rotary pinch bar creasers which instantaneously and simultaneously crease parallel longitudinal lines in advancing blanks with the blanks at zero velocity relative .to the creaser bars thereby eliminatingscuffing or *abrading which weaken the blank.

A further object of the invention is toprovide registration means on a pair of rotating creaser bars which 2,949,065 Patented Aug. 16, 1960 accurately locates each successive blank on the barsregardlessof their spacing and then retracts out of the way of the blanks after creasing.

Still another object of the invention is to provide pinch creasing mechanism on a pair of rotating creaser bars which creates an inverted U-shaped rib crease in corrugated paper stock Without fracturing, scarring or cutting the liners or flutes thereof.

A still further object of the invention is to provide a method and apparatus for creasing corrugated paperboard wherein parallel longitudinal creases'are applied simultaneously with no lateral strain on the stock and wherein slippage of theblanks relative to the blank carriers produces beneficial, rather than harmful, efiects.

Other objects and advantages of the invention will be apparent from the claims, the description of the drawings and from the drawings in which:

Fig. 1 is a plan view of creasing apparatus in accordance with the invention.

Fig. 2 is a side elevation of the devicein section on line 2-2 of Fig. 1.

Fig. 3 is an end elevation on line 33 of Fig. 2.

Fig. 3A is a somewhatdiagrammatic side elevation of the variable pressure mechanism on the carrier belts in the creasing zone of the invention.

Figs. 4 and 5 are enlarged, fragmentary, detail views of the creaser bar mechanism of the invention increasing and non-creasing position.

Figs. 69 are furthergenlarged detail views of the improved pinch creaser mechanism ,carried'by thecreaser bars in various-stages of operation.

Fig. 9A is an enlarged diagrammatic view of the crease achieved by the creaser means of the invention.

Fig. 10 is an enlarged fragmentary side elevation of the creaser bar mechanism.

Figs. 11-14 are somewhat diagrammatic views similar to Fig. 10 showing the cycle of operation of the crease l (52 Fig. 15 is an enlarged detail v1ew, in sect1on, show1ng the registration means carried by one of the creaser bars, and

Fig. 15A is afront elevation of one of the removable barrier members of the registration means of the inthe frame 20 of the machine and frame .20 includes side frame pieces 21 and 22 connected by'transverse frame members such as at 23. At the leftof Fig. 2 a portion of the feedzone .is illustrated including a stack 24 of identical box blanks of corrugated paperboard such as 25.

Each blank such as 25, as best shown in Fig. 1, in-

cludes side wall panels 26,27, 28 and29 and a glueflap 30 all defined by the lateral fold lines .32 and 33 and the longitudinal fold lines 35, 3 6, 37 and 38. .Box bottom flaps 4t 41, 42 and 43 and box cover flaps 44, 45, 46 and 47 are defined by the central slits 50 and 51 and the outer slits 52, 53, 54 and 55. The blanks 24, to be creased by the apparatus of this invention, may be preformed, as shown, with the crease or fold lines at 35 and 37, or with lines 35 and 37 uncreased, but in any case, the apparatus is designed to form an accurate,

straight, longitudinal crease alonglines 35 and 37 to assure the accurate-folding of the blank into a collapsed tubular box along these lines.

It will be understood that corrugated paperboard, unlike ordinary card board or paperboard, is fluted and of substantial thickness. It is also used principally for large size containers whereby the blanks may be five or six feet or more in width although sometimes only one or two feet in longitudinal dimension. For example, in the blank 25, the fold lines and 37 are formed in a relatively narrow web of the material and when the panels 40, 26 and 44 and the panels 43, 29 and 47 are overfolded inwardly to form a box, at high speed, misaligned corrugated flutes, air resistance or the twist effect of folder belts may tend to misalign the fold on lines 35 and 37 unless that fold is on a well defined crease line. The ordinary crease produced by conventional creaser rolls is not satisfactory for the purpose but the method and apparatus of this invention has proved to successfully apply a well defined, linear, longitudinal crease simultaneously to the. lines 35 and 37 of successive, spaced blanks upon which the panels may be folded inwardly in unusually accurate alignment.

As shown in Fig. 2 the flat blanks such as 25 are advanced individually and successively, in longitudinally spaced apart relation, from the bottom of stack 24 under the adjustable gate 56 and into the nip 57 of opposed feed rolls 58 and 59. The spaced blanks are then advanced into the nip 60 of a pair of upper and lower endless belt carriers 61 and 62 for frictional advance thereby along a path through the creasing zone 63 of the machine.

The upper carrier belt 61 is trained around the pulley 64, on a lateral shaft 65, and thence around suitable idler and tension pulleys such as 66 and 67 and under spaced pressure rolls 68 carried by an elongated roll supporting member 69. Similarly the lower carrier belt 62 is trained around the pulley 71, on a lateral shaft 72 and thence over spaced pressure rolls 73 carried by an elongated roll supporting member 74. The carrier belts 61 and 62 extend the full length of the machine through the creasing zone 63 and thence through the succeeding glueing, folding, or other treatment zones not shown, and the carrier belts are located in the central, vertical, longitudinal plane of the machine in alignment with the central slits 50 and 51. Because of the unusually well defined creases simultaneously applied along lines 35 and 37 by the creaser apparatus of this invention, it is possible to fold the blanks into boxes while being carried only by a single set of central upper and lower belts without the blanks twisting out of longitudinal alignment during the folding operation.

The upper roll supporting member 69 is coextensive longitudinally with the upper carrier belt 61 and is supported by lugs such as 75 and 76 pivotally connected to levers such as 77 and 78 pivoted to depending frame pieces such as 79 and 80. A rotatable shaft 82 is coextensive with belt 61 and includes eccentrics such as 83, turnable in cages such as 84 and arranged to raise and lower levers 77 and 78 when the shaft is turned by a worm gear connection 85 and lateral shaft 86. Thus the upper presser rolls 68 may be raised or lowered in the creasing zone and, in fact, along the full length of the machine, simultaneously to accommodate blanks of various thickness and to positively and unyieldably exert the desired downward pressure on the upper carrier belt 61.

The lower roll supporting member 74 is also coextensive longitudinally with the carrier belts 61 and 62 but the individual pressure rolls such as 73 in the creasing zone are mounted on bell crank levers such as 87 centrally pivoted as at 88 to member 74. The lower ends of each bell crank lever 87 are bifurcated to straddle a longitudinally extending rod 92 mounted to slide forwardly and rearwardly parallel to the paper line.

A collar 89 is fixed to rod 92 on one side of each lever 87 and a collar 90 is fixed on the opposite side thereof with a spring 91 between the collar and the lever. Thus when the rod 92 actuates the levers 87 to increase presvertical parallel side faces 165 and 166.

sure of the carrier belts the resulting pressure is uniform and in accordance with the predetermined constant pressure of the coil springs 91.

As best shown in Fig. 2 and Fig. 3A, rod 92 is actuated by a short crank arm 93 on lateral shaft 94, shaft 94 being actuated by a long spring loaded crank arm 95 having a roller cam follower 96 thereon. Follower 96 is actuated by cam 97 on shaft 98 and stub shaft 98 is rotated by the gear 99.

The pressure applied by the pivoted lower presser rolls 73 in the creasing zone is thus alternately increased and decreased in synchronism with the operation of the creaser apparatus to be described hereafter and with the speed of the carrier belt apparatus. As shown in Fig. 2, the gear reducer 1011, powered by the longitudinal drive shaft 102, in turn powers lateral shaft 103 carrying sprocket 104. Sprocket 104 through chain 105 drives sprocket 106 on lateral shaft 72, the shaft 72 carrying lower carrier belt pulley 71 and a gear 108. Gear 108 is enmeshed with a gear 109 on the lateral shaft 65 which carries the upper carrier belt pulley 64. Gear 108 is also enmeshed with the gear 99 of the presser roll mechanism and with gear 111 which drives gears 112 and 113 of the feed rolls 58 and 59. The mechanism indicated at 114 is part of the feed mechanism of the machine and is described in detail in myco-pending application thereon, Serial No. 698,868 filed November 25, 1957, now US. Patent No. 2,912,239.

The creaser means of the invention includes a pair of upper and lower creaser sub frames 115 and 116 on one side of the central carrier belts 61 and 62 and another pair of upper and lower creaser sub frames 117 and 118 on the other side of the central carrier belts 61 and 62. The sub frames 115, 116, 117 and 118 are laterally slideable on transverse tracks 120, 121, 122 and 123 (Fig. 10) and are movable thereon by threaded rods such as 124, 125, 126 and 127 operable from the side of the machine. An upper drive shaft 128, having a keyway 129, extends laterally across the machine and through the upper sub frames 115 and 117, there being a drive sprocket such as 131 and 132 in the upper portion of each sub frame, keyed to the shaft for rotation in any transverse position of the sub frame. A lower drive shaft 133, having a keyway 134, extends laterally across the machine for driving the keyed sprockets 135 and 136 in the lower portion of lower sub frames 116 and 118 in a similar manner. Shaft 133 carries a gear 150 meshed with a gear 141 carried by stub shaft 130. As best shown in Fig. 2 the transverse keyed drive shaft 128 and the stub shaft 130 carry sprockets 137 and 138, outside frame 21 and driven by the chain 139 from a gear reducer 140 powered by main drive shaft 102. Chain 139 is trained around a tension pulley 142 and the upper creaser frames 115 and 117 are movable in a vertical plane by turn screws such as 143 and 144 for adjusting the height thereof above the paper line 145 in accordance with various thicknesses of blanks.

Within each sub frame such as 117 the keyed drive sprocket such as 132 drives a pair of sprockets 146 and 147, by means of a silent type chain 148, there being a tension sprocket 149 for the chain. Each sprocket such as 146 is fast on a stub shaft 151 journalled in the sub frame in suitable bearings 152 and 153 (Fig. 4). Each shaft 151 carries a driver member 154 having one of the creaser bars such as 155, 156, 157 or 158, rotatably supported by a pin 159 near the periphery thereof. A counterweight 161 is mounted on each driver member 154 diametrically opposite to each pin 159. Suitable bearings 162 are provided near the opposite ends of each creaser bar for the pins 159 and the upper and lower creaser bars are moved, in parallelism, in orbital paths toward and away from each other as shown in Figs. ll-l4.

The two lower creaser bars 156 and 158 are identical and each includes a flat planar, upper face 163 having a single straight upstanding, elongated blade, or die, memher 164, centrally located thereon, the blade 164 having As shown in Figs. 6-9 the horizontal face 163 is preferablyformed on a detachable plate 167.having dependingintegral pins such as 168 held in place in the bar 156 by suitable set screws 169. The blade 164 tits in a slot .171 in plate 167 and in a groove 172 in bar 156 therebeing a set screw 173 for adjusting the height ofthe upper edge v174 above the face163. The upper edge ,174 of blade 164 is-.preferably slightly rounded along .the .corners as shown.

The two upper creaser bars 155rand :157are alsojidentical and each includesjalpairjofwside plates 175 and 176 connected by bolts suchas 17,7 -andeach upper bar also includes a central, upstanding tubular element 178 (Fig. 16). Element ,178 contains a .coil spring 179 bearing against the head 181 ofta piston 182, the lowertend 183 of piston 182 being fixed to an elongated rod or cylindrical guide 184 of circular ,crosssection extending the full length of the creaser bar. A threaded cap 185 isprovided to adjust the pressure of coil spring 179and a threaded collar 186 is provided to cooperate with the internal shoulder 187 in adjusting the stroke of the piston. Each upper creaser'bar 115 and 117 includes a pair of parti- .circular pincer blades 190 and 191, the internal arcuate faces 192 and 193 thereof slideably engaging the exterior face of rod 184 for movement therearound in a circular path, concentric with the axis of the rod. The exterior arcuate faces 194 and 195 of each parti-circular' blade 190 and 191 are pivotally connected intermediate thereof to the adjacent side plate 175 or 176 by a longitudinal pivot pin 196 or 197. In non-creasing position shown in Figs. 4, 6 and 16 the upper side edge faces 198 and 199 of blades 190 and 191 form an open slot 201 which converges outwardly while the lower side edge faces 202 and 203 thereof form an open slot 204 which diverges outwardly.

It will be understood that the two upper creaser bars 155 and 157 and the two lower creaser bars 156 and 158 rotate in unison in the direction of the arrows (Figs. 11- 14) to simultaneously apply a linear pinch crease along the longitudinal fold lines 35 and 37 of each successive blank 25 advanced through the creasing zone 63 by the friction carrier belts 61 and 62. Registration means 206 is provided on the lower creaser bars 156 and 158 which operates even though the blanks continue advancing along the paper line of the machine.

As best shown in Fig. 15, registration means 206 includes a barrier member 207 having an actuating rod 208 axially slideable in avertical hole 209 in a bar such as 156. A plunger notch 211 is located in rod 208 having a face .212 inclined at about 45 to engage a corresponding face 213 of the plunger 214. Plunger 214 is spring loaded by spring 215 to exert a continuous downwardly inclined frictional pressure on the rod .208 to maintain the rod in barrieror-non barrier position. A buffer plate 216 is provided on each lower sub frame 116 and 118 proximate the lower portion of the path of the lower tip 217 of each rod 208. The barrier members 207 are located at the ends of the creaser bars 156 and 158 and, as shown in Fig. 11, are moved upwardly into blank intercepting position at the bottom of the stroke of the lower creaser bars when the lower tip 217 of each rod208 strikes the fixed buffer plates such as 216. The barrier members 207, as shown in Fig. 12 rise above the paper line into the space between blanks to bar the advance of each successive blank being advanced by the belts 61 and 62 at a predetermined uniform surface speed. The creaser bars, however, while advancing temporarily in the same direction as the blanks during creasing, are travelling at a lesser predetermined surface speed. At this time the lower pressure rolls also temporarily release their pressure on the lower carrier belt 62 to temporarily assist the slippage of the blanks being creased relative to thebelts. Thus each blank 25 is advanced by the belts up to the rotating barrier members 207 on the lower creaser bars 156 and 158 where -uponthe blank is registeredwith the creaser bars and ad- -vances. at-thesurface speed of the creaser bars while the ..carricr;belts. temporarily slip. on the blank. As shown in Fig. 13 the upper tip 218 of each barrier member 207 is .the blades 190 and 191.

engaged-by the laterally aligned upper'creaserbar, such {3S .157, as :,that bar rotatesrdownwardly into creasing engagement and the member 207 is pusheddownwardly in thehole 209 against the friction exerted by plunger 214.

As the two creaser bars of each pair come togetherto grip. and crease theblank the. plunger face 213 engages the inclined ,face 217 of rod .208 and spring presses the rod into .its full downward position with member 207 below .the paper line in non-barrier position. .The blank 25.is .thus immediatelyreleasedto the carrier belts 61 and 62 as soon as the creasing operation is completedand the creaserbars move awayfrom each other.

.A second pair. ofregistration means 220 is preferably provi ded, identical .with-means.206, but positioned inter- .mediate-of thelengthof the lower creaser bars 156 and 158. .Therbarrier members v207,'as shown in Fig. 15A, are bifurcated at 221 and fit within a slot 222'in the upper tip of ,r0d.,208 in order that they may be snapped on and off the transverse bolts '223and 224 inrod 208. The creaser ,bars 155, 156, .157 and .158 are over .four feet in length and can, therefore, apply a crease of equivalent length to large size-blanks runone up. With such blanks .the barrier members 207 of the second registration means 220 are manually removed from their respective rods 208 to make the meansinoperable. However, with blanks of less length, both registrationmeans 206 and 220 are used and the blanks are run two up with the creaser bars creasing two blanks at a timeand then releasing the same to thecarrier belts.

vAs best shown in Fig. 6 the b1anks 25, registered on the creaser bars 156 and 158 by the barrier members 207 are supported on the top edge 174 of the single blades '164.as the upper creaser bars and 157 approach creasing position. The side edgefaces 202 and 203 of the pincer blades 190 and 1-91 are still divergent and the the parti-ci-rcular blades 190 and-191 have flattened the ,corrug-ated flutes and compressed the upper and lower liners together until the flat planar face 163 of the lower creaser bar 156, through the liners and deformed flutes offers substantial resistance to the-further advance of At this point the side plates and 176 continue to approach the lower creaser bar,

.and through the pivot pins 196 and 197 force the parti-circular blades 190 and 191 to slide in a circular path around the resiliently yieldable cylindrical rod 184 thereby tending to narrow the slot 204 and to place the lower side edge faces 202 and 203 in substantial parallelism with .the parallel side walls 165 and 166 of the anvil blade 164. A pinching action thus occurs in which an inverted U shaped crease is formed with substantially parallel legs and with the flutesof the corrugated board deformed and flattened as shown. It will be understood that the crease formed by this operation is to be used for a overfold in which the hingedly connected members are parallel to each other. The U-shaped crease .will beon the inside of thisfold and the thoroughly deformed stock at the crease not only yields easily to'the action of the folder belts'but assumes the parallel position shown much enlarged in Fig. 9A to make a neat and flat corner edge useful in the stacking operation.

The angle formed by each side edge face 202 or 203 with its respective adjoining exterior arcuate face 192 or 193 is nearly 90 whereby relatively broadstrips, such as 230 and 231 and 232 and 233, of the fluted corrugated .material are flattened on each side of the centrelines 234 and 235 of the resulting pinch crease. It is this characteristic of the fold accomplished by the creasers appatratus. of this invention which I permits :the permanent, tinbeaded and unfractured fold shown in Fig. 9A.

'in box blanks of paperboard, by the use of a pair of opposed creaser bars which comprises the steps of frictionally advancing said blanks individually and successively in spaced apart relation longitudinally along a path at a predetermined speed; rotating said creaser bars to advance along said path at less than the predetermined speed of said blanks; temporarily intercepting and registering each successive blank with said creaser bars while showing said blank to a reduced speed; simultaneously pinch creasing each said blank along parallel, linear, longitudinal crease lines while the blank is so registered with said creaser bars and so advancing at reduced speed and then releasing each said registered and creased blank from said creaser bars to resume frictional advance in spaced apart relation along said path at said predetermined speed.

2. In a machine for making paper boxes having a feed zone, a creasing zone and a folding zone the combination of frictional endless carrier means extending from said feed zone, through said creasing zone into said folding zone for advancing paper box blanks individually and successively in spaced apart relation longitudinally through said zones at a predetermined carrier speed; a plurality of pairs of upper and lower, elongated creasing bars rotatably mounted in said creasing zone, each pair adapted to form a longitudinal, linear crease in said blanks; means in said creasing zone rotating each said pair of creasing bars simultaneously into and out of engagement with each successive blank and advancing said blank at reduced speed through said creasing zone for applying parallel longitudinal linear pinch creases thereto and blank registration means on said machine, independent of said carrier means, for registering each successive blank relative to said creaser bars prior to the creasing thereof.

3. A combination as specified in claim 2 wherein said endless carrier means comprises a single pair of upper and lower carrier belts laterally positioned along the path of e the centre slits in said blanks.

4. A combination as specified in claim 2 wherein said frictional endless carrier means includes mechanism for reducing the frictional engagement thereof with said blanks in said creasing zone.

5. In a machine for making paper boxes frictional endlms carrier means for advancing paper box blanks individually and successively in spaced relation longitudinally along a path at a predetermined speed; rotatable creaser bar means along said path for simultaneously pinch creasing a plurality of parallel, linear, longitudinal crease lines in each said advancing means for rotating said creaser bar means at a surface speed less than said predetermined speed of said blanks and registration means,

mounted on said rotatable creaser bar means, for temporarily registering each said blank just prior to the pinch creasing thereof.

6. A combination as specified in claim 5 wherein each said creaser bar means comprises a pair of upper and lower creasing bars equal in length to the length of the longitudinal fold lines of the maximum size blank to be folded on said machine and includes a plurality of said registration means longitudinally spaced along said creaser bar means whereby two or more blanks of less than half said maximum length may be registered and creased simultaneously in said machine.

7. A combination as specified in claim 5 wherein said frictional endless carrier means includes mechanism for reducing frictional blank engagement along the portion of said blank path in which said creaser bar means is positioned.

8. A combination as specified in claim 5 wherein said creaser bar means includes upper and lower creaser bars traveling in an orbital path toward and away from each other and said registration means includes a retractable blank barrier member carried by one said bar and extending toward the other said bar and mechanism for retracting said member upon the creasing engagement of said bars.

9. Corrugated box blank creasing apparatus comprising a pair of upper and lower carrier belts frictionally advancing said blanks individually and successively along a longitudinal path at a predetermined speed; a pair of rigid, longitudinally extending, creaser bars mounted to rotate in parallelism on opposite sides of said path, said bars advancing with, and pinch creasing, each successive blank along a linear, longitudinal crease line during said rotation; means for rotating said bars to advance with said blanks at less surface speed than the predetermined speed of said blanks; a blank barrier member on one of said creaser bars movable into, and out of, the path of said blanks and mechanism associated with said creaser bars, moving said barrier into said path to register each successive blank thereon as said bars converge toward each other and moving said barrier out of said path to release said blanks to said carrier belts before said bars diverge away from each other.

10. In creasing apparatus of the type having a pair of opposed, creaser bars rotating in parellelism toward and away from the path of the articles to be creased the combination of a single, straight blade centrally projecting from a flat planar face on one said bar, said blade having parallel side faces; a pair of parti-circular blades on the other said bar, each having a flat planar, side edge face normally forming an outwardly divergent slot therebetween for receiving said single blade; means on both said bars for compressing and crushing spaced parallel strips of the material of said articles on opposite sides of said single blade as said bars advance toward each other and untimed, mechanical means, automatically actuated by substantial resistance to further advance of said bars toward each other said other bar for thereafter angularly sliding said pair of blades in a circular path toward said single blade in a pinching movement until said slot faces are in substantial parallelism with each other and to the side faces of said single blade.

11. A combination as specified in claim 10 wherein said mechanical means for angularly sliding said pair of blades in a circular path includes an elongated, cylindrical rod concentrically positioned between said blades, :1 pair of pivot pins each connecting the intermediate exterior portion of said blades to said bar; a spring loaded rod mounted in said bar to urge said cylinder and blades resiliently outwardly against creasing pressure tending to urge said cylinder and blades inwardly relative to said bar and means for adjusting the load exerted by said spring to vary the pinch creasing effect of said creaser bar.

12. In creasing apparatus of the type having a pair of opposed creaser bars rotating in parallelism toward and away from the path of the articles to be creased, the combination of an article barrier member movably mounted on one said bar to shift from barrier position to non barrier position; means for advancing said member into barrier position with each revolution of said creaser bars and means for retracting said member into nonbarrier position during each said revolution of said creaser bars.

13. A combination as specified in claim 12 wherein said barrier member includes an actuating rod axially slideable in a hole in said bar, said rod having a plunger notch intermediate of the length thereof and said retraction means includes a spring pressed plunger proximate the bottom of said hole, said plunger entering said notch when said barrier member nearly reaches nonbarrier position to snap said member entirely into said non-barrier position.

14. A combination as specified in claim 12 wherein the means for moving said member into barrier position comprises an element fixed in the path of said member, when said bars are diverging from each other, said element advancing said member into barrier position and said retraction means includes a spring loaded plunger frictionally but yieldably maintaining said member in said barrier position.

15. A combination as specified in claim 2 wherein each said creasing bar is co-extensive longitudinally with the longitudinal field lines of the maximum size blank to be folded on said machine and each pair of said creasing bars includes a pair of said blank registration means, longitudinally spaced apart a distance equal to one half said maximum length, whereby two or more blanks of less than half said maximum length may be creased simultaneously in said machine.

References Cited in the file of this patent UNITED STATES PATENTS Hawkins June 13, Moore Dec. 3, Stortz June 17, Smith Aug. 12, Greenwood Oct. 23, 1934 Bobst Oct. 14, Fischer Feb. 18, Nelson Feb. 3,

FOREIGN PATENTS Germany June 28,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N03 2349,0661 August 16, 1960 Leon E; La Bombard s in the-printed specification It is hereby certified that error appear tion and that the said Letters of the above numbered patent requiring correc Patent should read as corrected below.

Column 7 line 11,- for "showing": read slowing line 52, for "advancing means? read advancing blank; means column 8, line 53% strike out fl'xsaid other barf.

Signed and sealed this 31st day of January 1961.

(SEAL) Attest:

KARL H. AXL INE' Attesting Ofiicer ROBERT C. WATSON Commissioner of Patents 

